cleanup torrent reference leaks

CHANGELOG.md

@@ -33,9 +33,8 @@
 - Do not return existing torrent object when duplicate torrent is added. Fire an
   `'error'` event instead.
 
-- Memory leak of `Torrent` object caused by `RarityMap`
-
-- Memory leak of `Torrent` object caused by `TCPPool`
+- Memory leaks of `Torrent` object caused by various internal subclasses of WebTorrent,
+  including `RarityMap`, `TCPPool`, `WebConn`, `Server`.
 
 - `client.ratio` and `torrent.ratio` are now calculated as `uploaded / received` instead
   of `uploaded / downloaded`.

lib/server.js

@@ -12,19 +12,22 @@ function Server (torrent, opts) {
   var server = http.createServer(opts)
 
   var sockets = []
+  var pendingReady = []
   var closed = false
 
-  server.on('connection', function (socket) {
-    socket.setTimeout(36000000)
-    sockets.push(socket)
-    socket.on('close', function () {
-      arrayRemove(sockets, sockets.indexOf(socket))
-    })
-  })
+  server.on('connection', onConnection)
+  server.on('request', onRequest)
 
   var _close = server.close
   server.close = function (cb) {
     closed = true
+    torrent = null
+    server.removeListener('connection', onConnection)
+    server.removeListener('request', onRequest)
+    while (pendingReady.length) {
+      var onReady = pendingReady.pop()
+      torrent.removeListener('ready', onReady)
+    }
     _close.call(server, cb)
   }
 
@@ -38,7 +41,15 @@ function Server (torrent, opts) {
     else server.close(cb)
   }
 
-  server.on('request', function (req, res) {
+  function onConnection (socket) {
+    socket.setTimeout(36000000)
+    sockets.push(socket)
+    socket.once('close', function () {
+      arrayRemove(sockets, sockets.indexOf(socket))
+    })
+  }
+
+  function onRequest (req, res) {
     debug('onRequest')
 
     // Allow CORS requests to specify arbitrary headers, e.g. 'Range',
@@ -61,10 +72,15 @@ function Server (torrent, opts) {
     var pathname = url.parse(req.url).pathname
     if (pathname === '/favicon.ico') return res.end()
 
-    if (torrent.ready) onReady()
-    else torrent.once('ready', onReady)
+    if (torrent.ready) {
+      onReady()
+    } else {
+      pendingReady.push(onReady)
+      torrent.once('ready', onReady)
+    }
 
     function onReady () {
+      arrayRemove(pendingReady, pendingReady.indexOf(onReady))
       if (pathname === '/') {
         res.setHeader('Content-Type', 'text/html')
         var listHtml = torrent.files.map(function (file, i) {
@@ -112,7 +128,7 @@ function Server (torrent, opts) {
       if (req.method === 'HEAD') res.end()
       pump(file.createReadStream(range), res)
     }
-  })
+  }
 
   return server
 }

lib/webconn.js

@@ -1,6 +1,3 @@
-// TODO: cleanup events
-// TODO: cleanup reference to parsedTorrent (i.e. Torrent object)
-
 module.exports = WebConn
 
 var BitField = require('bitfield')
@@ -15,37 +12,41 @@ inherits(WebConn, Wire)
 /**
  * Converts requests for torrent blocks into http range requests.
  * @param {string} url web seed url
- * @param {Object} parsedTorrent
+ * @param {Object} torrent
  */
-function WebConn (url, parsedTorrent) {
-  var self = this
+function WebConn (url, torrent) {
   Wire.call(this)
 
-  self.url = url
-  self.webPeerId = sha1.sync(url)
-  self.parsedTorrent = parsedTorrent
+  this.url = url
+  this.webPeerId = sha1.sync(url)
+  this._torrent = torrent
+
+  this._init()
+}
 
+WebConn.prototype._init = function () {
+  var self = this
   self.setKeepAlive(true)
 
-  self.on('handshake', function (infoHash, peerId) {
+  self.once('handshake', function (infoHash, peerId) {
+    if (self.destroyed) return
     self.handshake(infoHash, self.webPeerId)
-    var numPieces = self.parsedTorrent.pieces.length
+    var numPieces = self._torrent.pieces.length
     var bitfield = new BitField(numPieces)
     for (var i = 0; i <= numPieces; i++) {
       bitfield.set(i, true)
     }
     self.bitfield(bitfield)
   })
 
-  self.on('choke', function () { debug('choke') })
-  self.on('unchoke', function () { debug('unchoke') })
-
   self.once('interested', function () {
     debug('interested')
     self.unchoke()
   })
-  self.on('uninterested', function () { debug('uninterested') })
 
+  self.on('uninterested', function () { debug('uninterested') })
+  self.on('choke', function () { debug('choke') })
+  self.on('unchoke', function () { debug('unchoke') })
   self.on('bitfield', function () { debug('bitfield') })
 
   self.on('request', function (pieceIndex, offset, length, callback) {
@@ -56,14 +57,14 @@ function WebConn (url, parsedTorrent) {
 
 WebConn.prototype.httpRequest = function (pieceIndex, offset, length, cb) {
   var self = this
-  var pieceOffset = pieceIndex * self.parsedTorrent.pieceLength
+  var pieceOffset = pieceIndex * self._torrent.pieceLength
   var rangeStart = pieceOffset + offset /* offset within whole torrent */
   var rangeEnd = rangeStart + length - 1
 
   // Web seed URL format:
   // For single-file torrents, make HTTP range requests directly to the web seed URL
   // For multi-file torrents, add the torrent folder and file name to the URL
-  var files = self.parsedTorrent.files
+  var files = self._torrent.files
   var requests
   if (files.length <= 1) {
     requests = [{
@@ -138,3 +139,8 @@ WebConn.prototype.httpRequest = function (pieceIndex, offset, length, cb) {
     })
   })
 }
+
+WebConn.prototype.destroy = function () {
+  Wire.prototype.destroy.call(this)
+  this._torrent = null
+}